[Premium-Rx] Anti-Static conductive foam warning

[Ciancone, Mark T.]

Nigel, on this side of the pond I have not seen this "degenerative" phenomenon in anti-static foam.
I have cursed the gooey breakdown of the occasionally-encountered non-anti-stat foam, however!

Mark/WB9APZ

-----Original Message-----
From: premium-rx-bounces at mailman.qth.net
[mailto:premium-rx-bounces at mailman.qth.net]On Behalf Of
GandalfG8 at aol.com
Sent: Thursday, July 24, 2008 1:11 PM
To: premium-rx at mailman.qth.net
Subject: [Premium-Rx] Anti-Static conductive foam warning



Apologies to those who might see this on more than one group or list and
apologies again if it's old news to everyone but me, but I did think it
important enough to share.

I've just retrieved a pair of ICs that have been dry stored as spares in a
component storage rack since 1979, a long time I know but probably not  unusual
for those of us using and maintaining older equipment.

These, as I thought anyway, were correctly stored with the pins pressed  into
black anti-static foam, the usual stuff that's been used for this  purpose
for years.
Unfortunately the foam has broken down into a sticky crumble and the  plating
on the IC pins is quite badly corroded, probably to the point  where they
won't take solder. A metal canned crystal lying against the foam has  also
corroded at the pont of contact.
I've seen this stuff turn into a gooey mess inside some instrument cases  but
hadn't previously even thought about the same thing  happening where it's
used used for component storage.

I've checked other trays and whilst not too many used this stuff but  where
they did there's evidence of similar problems.
I've even got a later large component rack, all ok so far but for how  long?,
where it was fitted from new to every drawer:-(

That's all, just offered as a word of warning to anyone else with  components
similarly stored.

regards

Nigel
GM8PZR





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